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Diffstat (limited to 'src/glsl/linker.cpp')
| -rw-r--r-- | src/glsl/linker.cpp | 871 |
1 files changed, 871 insertions, 0 deletions
diff --git a/src/glsl/linker.cpp b/src/glsl/linker.cpp new file mode 100644 index 0000000000..ba382fe881 --- /dev/null +++ b/src/glsl/linker.cpp @@ -0,0 +1,871 @@ +/* + * Copyright © 2010 Intel Corporation + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice (including the next + * paragraph) shall be included in all copies or substantial portions of the + * Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER + * DEALINGS IN THE SOFTWARE. + */ + +/** + * \file linker.cpp + * GLSL linker implementation + * + * Given a set of shaders that are to be linked to generate a final program, + * there are three distinct stages. + * + * In the first stage shaders are partitioned into groups based on the shader + * type. All shaders of a particular type (e.g., vertex shaders) are linked + * together. + * + * - Undefined references in each shader are resolve to definitions in + * another shader. + * - Types and qualifiers of uniforms, outputs, and global variables defined + * in multiple shaders with the same name are verified to be the same. + * - Initializers for uniforms and global variables defined + * in multiple shaders with the same name are verified to be the same. + * + * The result, in the terminology of the GLSL spec, is a set of shader + * executables for each processing unit. + * + * After the first stage is complete, a series of semantic checks are performed + * on each of the shader executables. + * + * - Each shader executable must define a \c main function. + * - Each vertex shader executable must write to \c gl_Position. + * - Each fragment shader executable must write to either \c gl_FragData or + * \c gl_FragColor. + * + * In the final stage individual shader executables are linked to create a + * complete exectuable. + * + * - Types of uniforms defined in multiple shader stages with the same name + * are verified to be the same. + * - Initializers for uniforms defined in multiple shader stages with the + * same name are verified to be the same. + * - Types and qualifiers of outputs defined in one stage are verified to + * be the same as the types and qualifiers of inputs defined with the same + * name in a later stage. + * + * \author Ian Romanick <ian.d.romanick@intel.com> + */ +#include <cstdlib> +#include <cstdio> +#include <cstdarg> + +extern "C" { +#include <talloc.h> +} + +#include "main/mtypes.h" +#include "glsl_symbol_table.h" +#include "glsl_parser_extras.h" +#include "ir.h" +#include "ir_optimization.h" +#include "program.h" +#include "hash_table.h" + +/** + * Visitor that determines whether or not a variable is ever written. + */ +class find_assignment_visitor : public ir_hierarchical_visitor { +public: + find_assignment_visitor(const char *name) + : name(name), found(false) + { + /* empty */ + } + + virtual ir_visitor_status visit_enter(ir_assignment *ir) + { + ir_variable *const var = ir->lhs->variable_referenced(); + + if (strcmp(name, var->name) == 0) { + found = true; + return visit_stop; + } + + return visit_continue_with_parent; + } + + bool variable_found() + { + return found; + } + +private: + const char *name; /**< Find writes to a variable with this name. */ + bool found; /**< Was a write to the variable found? */ +}; + + +void +linker_error_printf(glsl_program *prog, const char *fmt, ...) +{ + va_list ap; + + prog->InfoLog = talloc_strdup_append(prog->InfoLog, "error: "); + va_start(ap, fmt); + prog->InfoLog = talloc_vasprintf_append(prog->InfoLog, fmt, ap); + va_end(ap); +} + + +void +invalidate_variable_locations(glsl_shader *sh, enum ir_variable_mode mode, + int generic_base) +{ + foreach_list(node, &sh->ir) { + ir_variable *const var = ((ir_instruction *) node)->as_variable(); + + if ((var == NULL) || (var->mode != (unsigned) mode)) + continue; + + /* Only assign locations for generic attributes / varyings / etc. + */ + if (var->location >= generic_base) + var->location = -1; + } +} + + +/** + * Determine the number of attribute slots required for a particular type + * + * This code is here because it implements the language rules of a specific + * GLSL version. Since it's a property of the language and not a property of + * types in general, it doesn't really belong in glsl_type. + */ +unsigned +count_attribute_slots(const glsl_type *t) +{ + /* From page 31 (page 37 of the PDF) of the GLSL 1.50 spec: + * + * "A scalar input counts the same amount against this limit as a vec4, + * so applications may want to consider packing groups of four + * unrelated float inputs together into a vector to better utilize the + * capabilities of the underlying hardware. A matrix input will use up + * multiple locations. The number of locations used will equal the + * number of columns in the matrix." + * + * The spec does not explicitly say how arrays are counted. However, it + * should be safe to assume the total number of slots consumed by an array + * is the number of entries in the array multiplied by the number of slots + * consumed by a single element of the array. + */ + + if (t->is_array()) + return t->array_size() * count_attribute_slots(t->element_type()); + + if (t->is_matrix()) + return t->matrix_columns; + + return 1; +} + + +/** + * Verify that a vertex shader executable meets all semantic requirements + * + * \param shader Vertex shader executable to be verified + */ +bool +validate_vertex_shader_executable(struct glsl_program *prog, + struct glsl_shader *shader) +{ + if (shader == NULL) + return true; + + if (!shader->symbols->get_function("main")) { + linker_error_printf(prog, "vertex shader lacks `main'\n"); + return false; + } + + find_assignment_visitor find("gl_Position"); + find.run(&shader->ir); + if (!find.variable_found()) { + linker_error_printf(prog, + "vertex shader does not write to `gl_Position'\n"); + return false; + } + + return true; +} + + +/** + * Verify that a fragment shader executable meets all semantic requirements + * + * \param shader Fragment shader executable to be verified + */ +bool +validate_fragment_shader_executable(struct glsl_program *prog, + struct glsl_shader *shader) +{ + if (shader == NULL) + return true; + + if (!shader->symbols->get_function("main")) { + linker_error_printf(prog, "fragment shader lacks `main'\n"); + return false; + } + + find_assignment_visitor frag_color("gl_FragColor"); + find_assignment_visitor frag_data("gl_FragData"); + + frag_color.run(&shader->ir); + frag_data.run(&shader->ir); + + if (!frag_color.variable_found() && !frag_data.variable_found()) { + linker_error_printf(prog, "fragment shader does not write to " + "`gl_FragColor' or `gl_FragData'\n"); + return false; + } + + if (frag_color.variable_found() && frag_data.variable_found()) { + linker_error_printf(prog, "fragment shader writes to both " + "`gl_FragColor' and `gl_FragData'\n"); + return false; + } + + return true; +} + + +/** + * Perform validation of uniforms used across multiple shader stages + */ +bool +cross_validate_uniforms(struct glsl_program *prog) +{ + /* Examine all of the uniforms in all of the shaders and cross validate + * them. + */ + glsl_symbol_table uniforms; + for (unsigned i = 0; i < prog->_NumLinkedShaders; i++) { + foreach_list(node, &prog->_LinkedShaders[i]->ir) { + ir_variable *const var = ((ir_instruction *) node)->as_variable(); + + if ((var == NULL) || (var->mode != ir_var_uniform)) + continue; + + /* If a uniform with this name has already been seen, verify that the + * new instance has the same type. In addition, if the uniforms have + * initializers, the values of the initializers must be the same. + */ + ir_variable *const existing = uniforms.get_variable(var->name); + if (existing != NULL) { + if (var->type != existing->type) { + linker_error_printf(prog, "uniform `%s' declared as type " + "`%s' and type `%s'\n", + var->name, var->type->name, + existing->type->name); + return false; + } + + if (var->constant_value != NULL) { + if (existing->constant_value != NULL) { + if (!var->constant_value->has_value(existing->constant_value)) { + linker_error_printf(prog, "initializers for uniform " + "`%s' have differing values\n", + var->name); + return false; + } + } else + /* If the first-seen instance of a particular uniform did not + * have an initializer but a later instance does, copy the + * initializer to the version stored in the symbol table. + */ + existing->constant_value = + (ir_constant *)var->constant_value->clone(NULL); + } + } else + uniforms.add_variable(var->name, var); + } + } + + return true; +} + + +/** + * Validate that outputs from one stage match inputs of another + */ +bool +cross_validate_outputs_to_inputs(struct glsl_program *prog, + glsl_shader *producer, glsl_shader *consumer) +{ + glsl_symbol_table parameters; + /* FINISHME: Figure these out dynamically. */ + const char *const producer_stage = "vertex"; + const char *const consumer_stage = "fragment"; + + /* Find all shader outputs in the "producer" stage. + */ + foreach_list(node, &producer->ir) { + ir_variable *const var = ((ir_instruction *) node)->as_variable(); + + /* FINISHME: For geometry shaders, this should also look for inout + * FINISHME: variables. + */ + if ((var == NULL) || (var->mode != ir_var_out)) + continue; + + parameters.add_variable(var->name, var); + } + + + /* Find all shader inputs in the "consumer" stage. Any variables that have + * matching outputs already in the symbol table must have the same type and + * qualifiers. + */ + foreach_list(node, &consumer->ir) { + ir_variable *const input = ((ir_instruction *) node)->as_variable(); + + /* FINISHME: For geometry shaders, this should also look for inout + * FINISHME: variables. + */ + if ((input == NULL) || (input->mode != ir_var_in)) + continue; + + ir_variable *const output = parameters.get_variable(input->name); + if (output != NULL) { + /* Check that the types match between stages. + */ + if (input->type != output->type) { + linker_error_printf(prog, + "%s shader output `%s' delcared as " + "type `%s', but %s shader input declared " + "as type `%s'\n", + producer_stage, output->name, + output->type->name, + consumer_stage, input->type->name); + return false; + } + + /* Check that all of the qualifiers match between stages. + */ + if (input->centroid != output->centroid) { + linker_error_printf(prog, + "%s shader output `%s' %s centroid qualifier, " + "but %s shader input %s centroid qualifier\n", + producer_stage, + output->name, + (output->centroid) ? "has" : "lacks", + consumer_stage, + (input->centroid) ? "has" : "lacks"); + return false; + } + + if (input->invariant != output->invariant) { + linker_error_printf(prog, + "%s shader output `%s' %s invariant qualifier, " + "but %s shader input %s invariant qualifier\n", + producer_stage, + output->name, + (output->invariant) ? "has" : "lacks", + consumer_stage, + (input->invariant) ? "has" : "lacks"); + return false; + } + + if (input->interpolation != output->interpolation) { + linker_error_printf(prog, + "%s shader output `%s' specifies %s " + "interpolation qualifier, " + "but %s shader input specifies %s " + "interpolation qualifier\n", + producer_stage, + output->name, + output->interpolation_string(), + consumer_stage, + input->interpolation_string()); + return false; + } + } + } + + return true; +} + + +struct uniform_node { + exec_node link; + struct gl_uniform *u; + unsigned slots; +}; + +void +assign_uniform_locations(struct glsl_program *prog) +{ + /* */ + exec_list uniforms; + unsigned total_uniforms = 0; + hash_table *ht = hash_table_ctor(32, hash_table_string_hash, + hash_table_string_compare); + + for (unsigned i = 0; i < prog->_NumLinkedShaders; i++) { + unsigned next_position = 0; + + foreach_list(node, &prog->_LinkedShaders[i]->ir) { + ir_variable *const var = ((ir_instruction *) node)->as_variable(); + + if ((var == NULL) || (var->mode != ir_var_uniform)) + continue; + + const unsigned vec4_slots = (var->component_slots() + 3) / 4; + assert(vec4_slots != 0); + + uniform_node *n = (uniform_node *) hash_table_find(ht, var->name); + if (n == NULL) { + n = (uniform_node *) calloc(1, sizeof(struct uniform_node)); + n->u = (gl_uniform *) calloc(vec4_slots, sizeof(struct gl_uniform)); + n->slots = vec4_slots; + + n->u[0].Name = strdup(var->name); + for (unsigned j = 1; j < vec4_slots; j++) + n->u[j].Name = n->u[0].Name; + + hash_table_insert(ht, n, n->u[0].Name); + uniforms.push_tail(& n->link); + total_uniforms += vec4_slots; + } + + if (var->constant_value != NULL) + for (unsigned j = 0; j < vec4_slots; j++) + n->u[j].Initialized = true; + + var->location = next_position; + + for (unsigned j = 0; j < vec4_slots; j++) { + switch (prog->_LinkedShaders[i]->Type) { + case GL_VERTEX_SHADER: + n->u[j].VertPos = next_position; + break; + case GL_FRAGMENT_SHADER: + n->u[j].FragPos = next_position; + break; + case GL_GEOMETRY_SHADER: + /* FINISHME: Support geometry shaders. */ + assert(prog->_LinkedShaders[i]->Type != GL_GEOMETRY_SHADER); + break; + } + + next_position++; + } + } + } + + gl_uniform_list *ul = (gl_uniform_list *) + calloc(1, sizeof(gl_uniform_list)); + + ul->Size = total_uniforms; + ul->NumUniforms = total_uniforms; + ul->Uniforms = (gl_uniform *) calloc(total_uniforms, sizeof(gl_uniform)); + + unsigned idx = 0; + uniform_node *next; + for (uniform_node *node = (uniform_node *) uniforms.head + ; node->link.next != NULL + ; node = next) { + next = (uniform_node *) node->link.next; + + node->link.remove(); + memcpy(&ul->Uniforms[idx], node->u, sizeof(gl_uniform) * node->slots); + idx += node->slots; + + free(node->u); + free(node); + } + + hash_table_dtor(ht); + + prog->Uniforms = ul; +} + + +/** + * Find a contiguous set of available bits in a bitmask + * + * \param used_mask Bits representing used (1) and unused (0) locations + * \param needed_count Number of contiguous bits needed. + * + * \return + * Base location of the available bits on success or -1 on failure. + */ +int +find_available_slots(unsigned used_mask, unsigned needed_count) +{ + unsigned needed_mask = (1 << needed_count) - 1; + const int max_bit_to_test = (8 * sizeof(used_mask)) - needed_count; + + /* The comparison to 32 is redundant, but without it GCC emits "warning: + * cannot optimize possibly infinite loops" for the loop below. + */ + if ((needed_count == 0) || (max_bit_to_test < 0) || (max_bit_to_test > 32)) + return -1; + + for (int i = 0; i <= max_bit_to_test; i++) { + if ((needed_mask & ~used_mask) == needed_mask) + return i; + + needed_mask <<= 1; + } + + return -1; +} + + +bool +assign_attribute_locations(glsl_program *prog, unsigned max_attribute_index) +{ + /* Mark invalid attribute locations as being used. + */ + unsigned used_locations = (max_attribute_index >= 32) + ? ~0 : ~((1 << max_attribute_index) - 1); + + glsl_shader *const sh = prog->_LinkedShaders[0]; + assert(sh->Type == GL_VERTEX_SHADER); + + /* Operate in a total of four passes. + * + * 1. Invalidate the location assignments for all vertex shader inputs. + * + * 2. Assign locations for inputs that have user-defined (via + * glBindVertexAttribLocation) locatoins. + * + * 3. Sort the attributes without assigned locations by number of slots + * required in decreasing order. Fragmentation caused by attribute + * locations assigned by the application may prevent large attributes + * from having enough contiguous space. + * + * 4. Assign locations to any inputs without assigned locations. + */ + + invalidate_variable_locations(sh, ir_var_in, VERT_ATTRIB_GENERIC0); + + if (prog->Attributes != NULL) { + for (unsigned i = 0; i < prog->Attributes->NumParameters; i++) { + ir_variable *const var = + sh->symbols->get_variable(prog->Attributes->Parameters[i].Name); + + /* Note: attributes that occupy multiple slots, such as arrays or + * matrices, may appear in the attrib array multiple times. + */ + if ((var == NULL) || (var->location != -1)) + continue; + + /* From page 61 of the OpenGL 4.0 spec: + * + * "LinkProgram will fail if the attribute bindings assigned by + * BindAttribLocation do not leave not enough space to assign a + * location for an active matrix attribute or an active attribute + * array, both of which require multiple contiguous generic + * attributes." + * + * Previous versions of the spec contain similar language but omit the + * bit about attribute arrays. + * + * Page 61 of the OpenGL 4.0 spec also says: + * + * "It is possible for an application to bind more than one + * attribute name to the same location. This is referred to as + * aliasing. This will only work if only one of the aliased + * attributes is active in the executable program, or if no path + * through the shader consumes more than one attribute of a set + * of attributes aliased to the same location. A link error can + * occur if the linker determines that every path through the + * shader consumes multiple aliased attributes, but + * implementations are not required to generate an error in this + * case." + * + * These two paragraphs are either somewhat contradictory, or I don't + * fully understand one or both of them. + */ + /* FINISHME: The code as currently written does not support attribute + * FINISHME: location aliasing (see comment above). + */ + const int attr = prog->Attributes->Parameters[i].StateIndexes[0]; + const unsigned slots = count_attribute_slots(var->type); + + /* Mask representing the contiguous slots that will be used by this + * attribute. + */ + const unsigned use_mask = (1 << slots) - 1; + + /* Generate a link error if the set of bits requested for this + * attribute overlaps any previously allocated bits. + */ + if ((~(use_mask << attr) & used_locations) != used_locations) { + linker_error_printf(prog, + "insufficient contiguous attribute locations " + "available for vertex shader input `%s'", + var->name); + return false; + } + + var->location = VERT_ATTRIB_GENERIC0 + attr; + used_locations |= (use_mask << attr); + } + } + + /* Temporary storage for the set of attributes that need locations assigned. + */ + struct temp_attr { + unsigned slots; + ir_variable *var; + + /* Used below in the call to qsort. */ + static int compare(const void *a, const void *b) + { + const temp_attr *const l = (const temp_attr *) a; + const temp_attr *const r = (const temp_attr *) b; + + /* Reversed because we want a descending order sort below. */ + return r->slots - l->slots; + } + } to_assign[16]; + + unsigned num_attr = 0; + + foreach_list(node, &sh->ir) { + ir_variable *const var = ((ir_instruction *) node)->as_variable(); + + if ((var == NULL) || (var->mode != ir_var_in)) + continue; + + /* The location was explicitly assigned, nothing to do here. + */ + if (var->location != -1) + continue; + + to_assign[num_attr].slots = count_attribute_slots(var->type); + to_assign[num_attr].var = var; + num_attr++; + } + + /* If all of the attributes were assigned locations by the application (or + * are built-in attributes with fixed locations), return early. This should + * be the common case. + */ + if (num_attr == 0) + return true; + + qsort(to_assign, num_attr, sizeof(to_assign[0]), temp_attr::compare); + + for (unsigned i = 0; i < num_attr; i++) { + /* Mask representing the contiguous slots that will be used by this + * attribute. + */ + const unsigned use_mask = (1 << to_assign[i].slots) - 1; + + int location = find_available_slots(used_locations, to_assign[i].slots); + + if (location < 0) { + linker_error_printf(prog, + "insufficient contiguous attribute locations " + "available for vertex shader input `%s'", + to_assign[i].var->name); + return false; + } + + to_assign[i].var->location = VERT_ATTRIB_GENERIC0 + location; + used_locations |= (use_mask << location); + } + + return true; +} + + +void +assign_varying_locations(glsl_shader *producer, glsl_shader *consumer) +{ + /* FINISHME: Set dynamically when geometry shader support is added. */ + unsigned output_index = VERT_RESULT_VAR0; + unsigned input_index = FRAG_ATTRIB_VAR0; + + /* Operate in a total of three passes. + * + * 1. Assign locations for any matching inputs and outputs. + * + * 2. Mark output variables in the producer that do not have locations as + * not being outputs. This lets the optimizer eliminate them. + * + * 3. Mark input variables in the consumer that do not have locations as + * not being inputs. This lets the optimizer eliminate them. + */ + + invalidate_variable_locations(producer, ir_var_out, VERT_RESULT_VAR0); + invalidate_variable_locations(consumer, ir_var_in, FRAG_ATTRIB_VAR0); + + foreach_list(node, &producer->ir) { + ir_variable *const output_var = ((ir_instruction *) node)->as_variable(); + + if ((output_var == NULL) || (output_var->mode != ir_var_out) + || (output_var->location != -1)) + continue; + + ir_variable *const input_var = + consumer->symbols->get_variable(output_var->name); + + if ((input_var == NULL) || (input_var->mode != ir_var_in)) + continue; + + assert(input_var->location == -1); + + /* FINISHME: Location assignment will need some changes when arrays, + * FINISHME: matrices, and structures are allowed as shader inputs / + * FINISHME: outputs. + */ + output_var->location = output_index; + input_var->location = input_index; + + output_index++; + input_index++; + } + + foreach_list(node, &producer->ir) { + ir_variable *const var = ((ir_instruction *) node)->as_variable(); + + if ((var == NULL) || (var->mode != ir_var_out)) + continue; + + /* An 'out' variable is only really a shader output if its value is read + * by the following stage. + */ + var->shader_out = (var->location != -1); + } + + foreach_list(node, &consumer->ir) { + ir_variable *const var = ((ir_instruction *) node)->as_variable(); + + if ((var == NULL) || (var->mode != ir_var_in)) + continue; + + /* An 'in' variable is only really a shader input if its value is written + * by the previous stage. + */ + var->shader_in = (var->location != -1); + } +} + + +void +link_shaders(struct glsl_program *prog) +{ + prog->LinkStatus = false; + prog->Validated = false; + prog->_Used = false; + + if (prog->InfoLog != NULL) + talloc_free(prog->InfoLog); + + prog->InfoLog = talloc_strdup(NULL, ""); + + /* Separate the shaders into groups based on their type. + */ + struct glsl_shader **vert_shader_list; + unsigned num_vert_shaders = 0; + struct glsl_shader **frag_shader_list; + unsigned num_frag_shaders = 0; + + vert_shader_list = (struct glsl_shader **) + calloc(2 * prog->NumShaders, sizeof(struct glsl_shader *)); + frag_shader_list = &vert_shader_list[prog->NumShaders]; + + for (unsigned i = 0; i < prog->NumShaders; i++) { + switch (prog->Shaders[i]->Type) { + case GL_VERTEX_SHADER: + vert_shader_list[num_vert_shaders] = prog->Shaders[i]; + num_vert_shaders++; + break; + case GL_FRAGMENT_SHADER: + frag_shader_list[num_frag_shaders] = prog->Shaders[i]; + num_frag_shaders++; + break; + case GL_GEOMETRY_SHADER: + /* FINISHME: Support geometry shaders. */ + assert(prog->Shaders[i]->Type != GL_GEOMETRY_SHADER); + break; + } + } + + /* FINISHME: Implement intra-stage linking. */ + assert(num_vert_shaders <= 1); + assert(num_frag_shaders <= 1); + + /* Verify that each of the per-target executables is valid. + */ + if (!validate_vertex_shader_executable(prog, vert_shader_list[0]) + || !validate_fragment_shader_executable(prog, frag_shader_list[0])) + goto done; + + + prog->_LinkedShaders = (struct glsl_shader **) + calloc(2, sizeof(struct glsl_shader *)); + prog->_NumLinkedShaders = 0; + + if (num_vert_shaders > 0) { + prog->_LinkedShaders[prog->_NumLinkedShaders] = vert_shader_list[0]; + prog->_NumLinkedShaders++; + } + + if (num_frag_shaders > 0) { + prog->_LinkedShaders[prog->_NumLinkedShaders] = frag_shader_list[0]; + prog->_NumLinkedShaders++; + } + + /* Here begins the inter-stage linking phase. Some initial validation is + * performed, then locations are assigned for uniforms, attributes, and + * varyings. + */ + if (cross_validate_uniforms(prog)) { + /* Validate the inputs of each stage with the output of the preceeding + * stage. + */ + for (unsigned i = 1; i < prog->_NumLinkedShaders; i++) { + if (!cross_validate_outputs_to_inputs(prog, + prog->_LinkedShaders[i - 1], + prog->_LinkedShaders[i])) + goto done; + } + + prog->LinkStatus = true; + } + + /* FINISHME: Perform whole-program optimization here. */ + + assign_uniform_locations(prog); + + if (prog->_LinkedShaders[0]->Type == GL_VERTEX_SHADER) + /* FINISHME: The value of the max_attribute_index parameter is + * FINISHME: implementation dependent based on the value of + * FINISHME: GL_MAX_VERTEX_ATTRIBS. GL_MAX_VERTEX_ATTRIBS must be + * FINISHME: at least 16, so hardcode 16 for now. + */ + if (!assign_attribute_locations(prog, 16)) + goto done; + + for (unsigned i = 1; i < prog->_NumLinkedShaders; i++) + assign_varying_locations(prog->_LinkedShaders[i - 1], + prog->_LinkedShaders[i]); + + /* FINISHME: Assign fragment shader output locations. */ + +done: + free(vert_shader_list); +} |